1. Field of the Invention
This invention relates to a novel use of 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivatives. Specifically, this invention relates to a cerebral-circulation-metabolism-function-improving agent comprising a 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivative as the effective ingredient.
2. Description of the Prior Art
Many lignans produced through condensation of cinnamyl pyrophosphate derivatives have been found in nature [Phytochemistry, 11, 1537 (1972)]. These lignans include various types of 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivatives such as pinoresinol and its congeners, and piperitol and its congeners which have been isolated from crude drugs such as Chinese gutta percha, korean forsythia fruit and zanthoxylum fruit (Japanese pepper). The chemical structures of the compounds have been determined.
The pharmacological effects of such 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivatives so far verified include the antihypertensive effect of 1,4-dihydroxy-1,4-bis(3,5-dimethoxy-4-hydroxyphenyl)butane-2,3-dicarboxyli c dilactones and 2,6-bis(hydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane glucosides (Japanese Patent Laid-Open Sho 52-102433 and 53-7698), the carcinostatic effect, the catechol-O-methyltransferase-inhibiting effect and the adenosine-3',5'-cyclic-phosphate-phosphodiesterase-inhibiting effect of 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane-4,8-dione derivatives and dehydrodicaffeic dilactone derivatives (Japanese Patent Laid-Open Sho 52-136193 and 54-73789), and the anticonvulsant effect, the tranquilizing effect and the antidepressant effect of sesamine and its congeners (U.S. Pat. No. 4,427,694).
As the population of aged people has greatly increased, cerebral apoplexy, cerebral infarction and senile dementia caused by cerebrovascular disorder, deteroriated nervous conduction or deteriorated energy metabolism have become a serious social problem and various types of agents have been developed (Japanese Patent Laid-Open Sho 55-17329, 59-219223 and 56-158713).
Since there is no drug for the cerebral circulation system which comprises the above 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivatives and there have been no reports on the above pharmacological effects, and there is thus still room for further study of the above 2,6-diphenyl-3,7-dioxabicyclo[3.3.0]octane derivatives in the field of medicines.